Cetirizine of the Formula (X) is prepared according to the state of the art by the hydrolysis of N,N-dimethyl-{2-[4-(α-phenyl-p-chlorobenzyl)-piperazin-1-yl]-ethoxy}-acetamide of the Formula (IX)

2-Chloroethoxy-acetic acid-N,N-dimethylamide of the Formula (I) is an important intermediate in the preparation of the compound of the Formula (IX) and the compound of the Formula (X) and optical isomers thereof.
A process for the preparation of 2-chloroethoxy-acetic acid-N,N-dimethylamide of the Formula (I) has been disclosed in German Publication Document No. 2 150 075. According to this process, 2-chloroethoxy-acetic acid and aqueous dimethylamine solution are reacted in presence of triethylamine and ethyl-chloroformate and the product 2-chloroethoxy-acetic acid-N,N-dimethylamide is distilled in vacuo. The disadvantage of this process resides in the fact that the cost of the reagents is relatively high as compared to the price of the product, and the purity of the product is not suitable for the purpose of the production of medicines.
Therefore the need arises for a process suitable for the preparation of 2-chloroethoxy-acetic acid-N,N-dimethylamide of the Formula (I) in the purity suitable for use in the production of pharmaceutical active ingredients.
The above objective is solved by the present invention.